In recent years, specifications for digital television are being formulated, and with this, an STB (Set Top Box) which is compliant with each of the specifications is being developed.
In the OCAP 1.0 specification (OCAP1.0 Profile OC-SP-OCAP1.0-IF-109-031121), which is a specification for North American cable broadcasting, various services (for example, an interactive program) can be provided by distributing to respective homes, not only video and audio, but also the applications attached to such video and audio. In addition, an application (for example, an electronic program guide) prepared by a broadcast operator can also be operated in an STB.
The “downloading of data” in patent reference 1 describes a method for downloading, from a broadcast wave (in other words, an MPEG2 transport stream), an application related to a broadcast and executing the downloaded application. With the technology described in patent reference 1, it becomes possible to distribute, not only video and audio, but also applications to respective homes.
Furthermore, the “method and apparatus for managing an application in accordance with application life cycle” in patent reference 2 describes a technology for application operation management. In the OCAP 1.0 specification, the management of life cycles of distributed individual applications is made possible with the use of the technology described in patent reference 2.
Furthermore, the OCAP 1.0 specification stipulates that, in the case where an application prepared by a broadcast operator exists at the time of STB activation, the application prepared by the broadcast operator must be activated, as well as reactivated in the case where the application prepared by the broadcast operator abnormally terminates.
By using the conventional technology, it becomes possible, after downloading and executing an application, to monitor the life cycle of the application and detect abnormal termination. In addition, it becomes possible to re-execute an application that abnormally terminates.    Patent Reference 1: Japanese Translation of PCT International Application laid open as JP2001-519627    Patent Reference 2: Japanese Translation of PCT International Application laid open as JP2003-504753